State officials agreed Wednesday to spend $4.8 million to complete design plans for a major renovation of the central Enoch Pratt Free Library.

The move indicates the state will approve additional funding for a $99 million renovation of the 1930s-era, 275,000-square-foot building starting next year, Pratt CEO Carla D. Hayden said.

"You don't need plans if you're not going to build something," Hayden said. "We're taking this as a good sign. It means a lot when you know that they are allowing you to really start with the planning documents."

The renovations, $6 million of which would be paid for by the city, would add bathrooms, elevators, air conditioning and heating units and updated security and fire protection systems. Plans also include environmentally friendly electrical and mechanical systems and energy-efficient windows, lighting and roofing to help the building merit a Leadership in Energy & Environmental Design silver certification.

The renovations would also update the library's information technology system and include laptop and smartphone docking ports at reading tables. At "tech-takeout" stations, patrons could download selections onto their tablets and e-readers. The library's historic architecture, woodwork, brass work and ornate ceilings would be restored, and the Edgar Allan Poe Room — which contains letters written by Poe and a lock of his hair — would be refurbished.

The project is expected to take three years and conclude in August 2018. The library will stay open during the construction, Hayden said, which might mean opening a "pop-up Pratt" nearby for overflow books.

The original design contract was awarded to Baltimore architectural firm Ayers Saint Gross in 1998 before a budget shortfall in 2001 suspended the project's funding. After a 2010 study, the firm was awarded a modified contract Wednesday. The construction would make up $73 million of the $99 million project.

Hayden said the renovations will help boost Maryland's reputation among other states as a "library heaven." Even in a time when some argue that the Internet has rendered libraries obsolete, the Pratt, with its 1.5 million volumes and 16-mm films, has thrived.

"All they have to do is look at the numbers," she said. "Last year 13 million people visited Maryland libraries and checked out 60 million items. There's Google, but they are asking librarians questions. People want high-tech, but they want high-touch."

Libraries serve as anchors for many of the state's communities, and programming, from visiting speakers to early childhood programs, gives people another reason to keep coming back, Hayden said. Maryland's libraries operate on a network that allows library cards to work across jurisdictions and books checked out at any of the state's 102 libraries to be returned at any other.

"We are homework help, jobs — people file online" at the libraries, Hayden said. "We are community centers. ... Not in just urban areas, out in rural areas, in Western Maryland, on the Eastern Shore."

The renovations will only affect the central library. For each of the past six years, the local branches of the Pratt have each gotten about $5 million from the state to supplement local government funding, Hayden said.